I did this mod when I recapped the board on my LC III. Though it took me awhile to figure out where R73 was because I couldn't find any pictures of said mod. Replacing the SMD caps was an immense pain in the ass and despite being super careful removing the caps, I still managed to lift two solder pads and accidentally rip one clean off the board (the one right on top of the SCSI port.) Fortunately there was a small bit of pad remaining that I could grab on to with a fat blob of solder. I was a tad worried when I got some of the caps off because the electrolyte had started eating traces. The machine works now (and much faster too) and hopefully it will stay that way for another 22 years. I recommend to everyone that has a Mac of this vintage to recap the logic board, even if you aren't experiencing problems yet, because you will and it can get very nasty. I lost a Performa 600CD to this, but considering it was a worthless model to begin with, I wasn't too upset. I also recommend that anyone doing this overclocking mod, especially on the earlier LC IIIs with 25 MHz 68030s to put heatsinks on the CPU and the VLSI chipset. Under normal operation the CPU will get hot enough to where you can't hold your finger on it for more than a few seconds. Overclocking brings it up much higher, to the point where a fan is almost necessary. Oh and you should put a 68882 in that empty socket, I've found the 40 MHz variant on Ebay for just a few dollars. Some software requires a FPU to run and some 3D games like Duke 3D and Marathon run a few frames faster with one.
The CPU in my LCIII is a 25Mhz one (says 25 on the chip, unlike yours that says 33). Can I still do this mod or is it only for LCIII’s that are lucky enough to have a ‘sleeping’ 33Mhz chip installed?
Any small heatsink with a pressure sensitive adhesive backing will do. The factory underclocked 33MHz version technically doesn't need it but I'd recommend it on the 25. The CPU and the main chipset get quite warm so stick one on each.
@@MadScientistsLair mine for some reason has an overclocked 16 but showed I have 25. Later I overclocked it to 33 and it is working fine and smoothly. Should a problem related happen, I’m reverting it back to 25 but for now it seems perfectly fine. May definitely need one a heat sink.
Got this mod done! Feels noticeably more responsive! Now if I can just get the VRAM slot working!
I did this mod when I recapped the board on my LC III. Though it took me awhile to figure out where R73 was because I couldn't find any pictures of said mod.
Replacing the SMD caps was an immense pain in the ass and despite being super careful removing the caps, I still managed to lift two solder pads and accidentally rip one clean off the board (the one right on top of the SCSI port.) Fortunately there was a small bit of pad remaining that I could grab on to with a fat blob of solder.
I was a tad worried when I got some of the caps off because the electrolyte had started eating traces. The machine works now (and much faster too) and hopefully it will stay that way for another 22 years.
I recommend to everyone that has a Mac of this vintage to recap the logic board, even if you aren't experiencing problems yet, because you will and it can get very nasty. I lost a Performa 600CD to this, but considering it was a worthless model to begin with, I wasn't too upset.
I also recommend that anyone doing this overclocking mod, especially on the earlier LC IIIs with 25 MHz 68030s to put heatsinks on the CPU and the VLSI chipset. Under normal operation the CPU will get hot enough to where you can't hold your finger on it for more than a few seconds. Overclocking brings it up much higher, to the point where a fan is almost necessary.
Oh and you should put a 68882 in that empty socket, I've found the 40 MHz variant on Ebay for just a few dollars. Some software requires a FPU to run and some 3D games like Duke 3D and Marathon run a few frames faster with one.
The CPU in my LCIII is a 25Mhz one (says 25 on the chip, unlike yours that says 33). Can I still do this mod or is it only for LCIII’s that are lucky enough to have a ‘sleeping’ 33Mhz chip installed?
You can do it but it will be an actual overclock and more likely to cause issues. Some benchmarking afterwards is a decent stability check.
What kind of heatsink should I use that would fit in my Lc III Plus since I have done the mod?
Any small heatsink with a pressure sensitive adhesive backing will do. The factory underclocked 33MHz version technically doesn't need it but I'd recommend it on the 25.
The CPU and the main chipset get quite warm so stick one on each.
@@MadScientistsLair mine for some reason has an overclocked 16 but showed I have 25. Later I overclocked it to 33 and it is working fine and smoothly. Should a problem related happen, I’m reverting it back to 25 but for now it seems perfectly fine. May definitely need one a heat sink.